SSIS - Flat File Location

I have a SSIS package that imports data from a flat file into a table. The
file is in a network share. The package itself is in my local machine. The
sql server itself is running on my local machine. This will be changed later
to a server.

The package runs fine from the BI studio. I have a job that executes this
package. I tried the following.

1. Used the network file in the package's connection manager. Used Operating
system command type and used
EXEC xp_cmdshell 'dtexec /f "...."' ---Failed with error "The system cannot
find the file specified"
2. Used the network file in the package's connection manager. Ran the same
command EXEC xp_cmdshell 'dtexec /f "...."' in the query window. - Same Error.
3. Used a local file in the package's connection manager. Used Operating
system command type and used EXEC xp_cmdshell 'dtexec /f "...."' ---Failed
with error "The system cannot find the file specified"
4. Used a local file in the package's connection manager. Ran the same
command EXEC xp_cmdshell 'dtexec /f "...."' in the query window. - Runs
FINE!!!
5. Used the SSIS package type in the job. Used the network file in the
package's connection manager. Failed with error "The package execution
failed."

Could someone please let me know where I am wrong? I am not a DBA, so I
probably am missing something that I haven't mapped or given access rights
to. But I do not understand where and what I should look for. Please help.

Thanks,
Sun.